Serial X-ray Research Articles

Pneumonia-related infiltration of the pericardium mimics pericardial effusion, with an echocardiographic finding, surgical result, and outcome

The pericardial sac in a healthy person holds 15–50 mL (mL) of serous fluid. Pericardial effusion (PE) is caused by an abnormal buildup of pericardial fluid in the space around the heart. We present here a 2-year-old healthy child who presented with shortness of breath, fever, and poor feeding for 2 days. Based on echocardiography and following the patient's condition detoriation, the patient was taken to the operation theater. Massive infiltration like substances were seen in the pericardial space instead of suspected pericardial effusion and the sample was sent to the pathology center. The child was extubated on day three postoperatively while serial lab tests, echocardiography, and chest x-ray follow-up demonstrated significant improvement. Follow up 1 week and 3 months later, the child's chest x-ray, inflammatory markers lab test, and echocardiography were normal.

Effect of ceftriaxone on intestinal transit time.

Ceftriaxone reduces gallbladder and ileal contractility. Many studies have shown that ceftriaxone causes biliary sludge and pseudolithiasis. However, its effect on intestinal transit time has not been investigated. This study aimed to investigate the effect of ceftriaxone on intestinal transit time. Sixteen rats were examined in two groups: The study group (group A, n= 8) was administered with 100 mg/kg ceftriaxone intramuscularly for 7days. The control group (group B, n= 8) was administered with intramuscular distilled water for 7days. On the seventh day, a mixture of 2ml barium and saline was given orally to both groups. Barium transit was evaluated using serial digital X-ray images. The stomach was full and the transition into the small intestine loop was observed in all rats at 45 min in both groups. At the 2nd hour, colonic transition was observed in two rats in group A (2/8, 25%) and in seven rats in group B (7/8, 87.5%). At the 4th hour, five (62.5%) rats in group A had transverse colonic transition, and all rats in group B (8/8, 100%) had transverse and/or left colonic transition. At the 6th hour, no rat in group A had rectal transition, and all rats in group B (8/8, 100%) had complete passage of colonic contrast material. Ceftriaxone significantly prolongs the small intestine transit time, large intestine transit time, and total intestinal transit times.

Deep learning of longitudinal chest X-ray and clinical variables predicts duration on ventilator and mortality in COVID-19 patients

ObjectivesTo use deep learning of serial portable chest X-ray (pCXR) and clinical variables to predict mortality and duration on invasive mechanical ventilation (IMV) for Coronavirus disease 2019 (COVID-19) patients.MethodsThis is a retrospective study. Serial pCXR and serial clinical variables were analyzed for data from day 1, day 5, day 1–3, day 3–5, or day 1–5 on IMV (110 IMV survivors and 76 IMV non-survivors). The outcome variables were duration on IMV and mortality. With fivefold cross-validation, the performance of the proposed deep learning system was evaluated by receiver operating characteristic (ROC) analysis and correlation analysis.ResultsPredictive models using 5-consecutive-day data outperformed those using 3-consecutive-day and 1-day data. Prediction using data closer to the outcome was generally better (i.e., day 5 data performed better than day 1 data, and day 3–5 data performed better than day 1–3 data). Prediction performance was generally better for the combined pCXR and non-imaging clinical data than either alone. The combined pCXR and non-imaging data of 5 consecutive days predicted mortality with an accuracy of 85 ± 3.5% (95% confidence interval (CI)) and an area under the curve (AUC) of 0.87 ± 0.05 (95% CI) and predicted the duration needed to be on IMV to within 2.56 ± 0.21 (95% CI) days on the validation dataset.ConclusionsDeep learning of longitudinal pCXR and clinical data have the potential to accurately predict mortality and duration on IMV in COVID-19 patients. Longitudinal pCXR could have prognostic value if these findings can be validated in a large, multi-institutional cohort.

Acceleration of bone formation by octacalcium phosphate composite in a rat tibia critical-sized defect.

BackgroundThe osteogenic capabilities and biodegradability of octacalcium phosphate (OCP) composites make them unique. Despite the excellent characteristics of OCP, their use is limited due to handling difficulties. In this study, we aimed to evaluate and compare three types of OCPs (cemented OCP (C-OCP), C-OCP with collagen (OCP/Col), and synthetic OCP (S-OCP) with alginate (OCP/Alg)) versus commercially available β-tricalcium phosphate (β-TCP) regarding their potential to accelerate bone formation in defective rat tibias.MethodsThe specimens with OCP composite were manufactured into 5 ​mm cubes and inserted into the segmental defects of rat tibias fixed with an external fixator. In addition, 3 ​mm-hole defects in rat tibias were evaluated to compare the graft material properties in different clinical situations. Serial X-ray studies were evaluated weekly and the tibias were harvested at postoperative 6 weeks or 8 weeks for radiologic evaluation. Histological and histomorphometric analyses were performed to evaluate the acceleration of bone formation.ResultsIn the critical-defect model, OCP/Alg showed bone bridges between segmentally resected bone ends that were comparable to those of β-TCP. However, differences were observed in the residual graft materials. Most β-TCP was maintained until 8 weeks postoperatively; however, OCP/Alg was more biodegradable. In addition calcification in the β-TCP occurred at the directly contacted area between graft particles and bony ingrowth was observed in the region adjacent resected surface of tibia. In contrast, no direct bony ingrowth was observed in OCP-based materials, but osteogenesis induced from resected surface of tibia was more active. In the hole-defect model, OCP/Col accelerated bone formation. β-TCP and OCP/Alg showed similar patterns with relatively higher biodegradability. In histology, among the OCP-based materials, directly contacted new bone was formed only in OCP/Alg group. The new bone formation in the periphery area of graft materials was much more active in the OCP-based materials, and the newly formed bone showed a thicker trabecular and more mature appearance than the β-TCP group.ConclusionsIn this study, OCP/Alg was equivalent to β-TCP in the acceleration of bone formation with better biodegradability appropriate for clinical situations in different circumstances. Our OCP/Col composite showed fast degradation, which makes it unsuitable for use in mechanical stress conditions in clinical orthopedic settings.The Translational Potential of this ArticleIn our research, we compared our various manufactured OCP composites to commercially available β-TCP in critical-defect rat tibia model. OCP/Col showed acceleration in hole-defect model as previous studies in dental field but in our critical-sized defect model it resorbed fast without acceleration of bony union. OCP/Alg showed matched results compared to β-TCP and relatively fast resorption so we showed market value in special clinical indication depending on treatment strategy. This is the first OCP composite study in orthopaedics with animal critical-sized tibia bone study and further study should be considered for clinical application based on this study.

MANAGEMENT OF PNEUMOTHORAX AND PNEUMOMEDIASTINUM IN COVID-19 PATIENTS WITH ARDS

SESSION TITLE: What Lessons Will We Take From the Pandemic?SESSION TYPE: Rapid Fire Original InvPRESENTED ON: 10/19/2022 11:15 am - 12:15 pmPURPOSE: Since the emergence of COVID-19, many serious complications have arisen especially in the setting of Acute Respiratory Distress Syndrome (ARDS) in the intensive care unit. Historically, ARDS and mechanical ventilation is associated with higher rates of pneumothorax. It has been well described that ARDS is the result of inflammatory lung injury, with increased activation of circulating neutrophils, complement and proinflammatory mediators leading to loss of surfactant, alveolar atelectasis, and fibrin deposition. This leads to a less compliant lung parenchyma, and higher airway pressures, which has been attributed as a risk factor for pneumothorax. The management of pneumothorax varies depending on the etiology of the pneumothorax. In the case of iatrogenic pneumothorax (i.e. mechanical ventilation), tube thoracostomy is generally recommended, however the size of the chest tube inserted remains less clear.METHODS: This is a multi-center retrospective cohort study of 88 hospitalized patients with a diagnosis of COVID-19 and pneumothorax or pneumomediastinum between the dates of 3/11/2020 to 01/26/2021. Patient demographics, comorbidities, laboratory and hemodynamic data were collected as well as ventilator settings, lung mechanics, and clinical patient outcome data including type of intervention and rate of resolution of pneumothorax. Final statistical analysis is pending.RESULTS: Our preliminary results reveal that there was a higher rate of resolution of pneumothorax with a large bore chest tube (LBCT) compared to a small bore chest tube (SBCT). There was no significant difference in lung compliance or tidal volume in cc/kg between the patients with a resolving pneumothorax compared to the patients with a nonresolving pneumothorax. Overall mortality rate among all patients was 70.4%.CONCLUSIONS: Patients with a large bore chest tube placed are more likely to have resolution of pneumothorax compared to small bore chest tube or serial X-ray. Lung compliance and tidal volume were not significantly different between patients that had a resolving pneumothorax compared to nonresolving pneumothorax. It is important to manage a pneumothorax early on to reduce associated morbidity.CLINICAL IMPLICATIONS: The development of pneumothorax in COVID patients with ARDS has significant associated morbidity and mortality. Utilization of a large bore chest tube may result in improved rates of resolution of pneumothorax.DISCLOSURES: No relevant relationships by Nathalie AntoniosNo relevant relationships by Colby BakerNo relevant relationships by Jessica JohnsonNo relevant relationships by Karen Sayad SESSION TITLE: What Lessons Will We Take From the Pandemic? SESSION TYPE: Rapid Fire Original Inv PRESENTED ON: 10/19/2022 11:15 am - 12:15 pm PURPOSE: Since the emergence of COVID-19, many serious complications have arisen especially in the setting of Acute Respiratory Distress Syndrome (ARDS) in the intensive care unit. Historically, ARDS and mechanical ventilation is associated with higher rates of pneumothorax. It has been well described that ARDS is the result of inflammatory lung injury, with increased activation of circulating neutrophils, complement and proinflammatory mediators leading to loss of surfactant, alveolar atelectasis, and fibrin deposition. This leads to a less compliant lung parenchyma, and higher airway pressures, which has been attributed as a risk factor for pneumothorax. The management of pneumothorax varies depending on the etiology of the pneumothorax. In the case of iatrogenic pneumothorax (i.e. mechanical ventilation), tube thoracostomy is generally recommended, however the size of the chest tube inserted remains less clear. METHODS: This is a multi-center retrospective cohort study of 88 hospitalized patients with a diagnosis of COVID-19 and pneumothorax or pneumomediastinum between the dates of 3/11/2020 to 01/26/2021. Patient demographics, comorbidities, laboratory and hemodynamic data were collected as well as ventilator settings, lung mechanics, and clinical patient outcome data including type of intervention and rate of resolution of pneumothorax. Final statistical analysis is pending. RESULTS: Our preliminary results reveal that there was a higher rate of resolution of pneumothorax with a large bore chest tube (LBCT) compared to a small bore chest tube (SBCT). There was no significant difference in lung compliance or tidal volume in cc/kg between the patients with a resolving pneumothorax compared to the patients with a nonresolving pneumothorax. Overall mortality rate among all patients was 70.4%. CONCLUSIONS: Patients with a large bore chest tube placed are more likely to have resolution of pneumothorax compared to small bore chest tube or serial X-ray. Lung compliance and tidal volume were not significantly different between patients that had a resolving pneumothorax compared to nonresolving pneumothorax. It is important to manage a pneumothorax early on to reduce associated morbidity. CLINICAL IMPLICATIONS: The development of pneumothorax in COVID patients with ARDS has significant associated morbidity and mortality. Utilization of a large bore chest tube may result in improved rates of resolution of pneumothorax. DISCLOSURES: No relevant relationships by Nathalie Antonios No relevant relationships by Colby Baker No relevant relationships by Jessica Johnson No relevant relationships by Karen Sayad

S2450 Acute Esophageal Necrosis: Low Flow Leading to Darkness

Introduction: Acute esophageal necrosis (AEN), commonly referred to as black esophagus due to the striking circumferential blackening of the esophageal mucosa, is a rare clinical condition with a prevalence of up to 0.2%. The etiology of this condition is unclear but thought to involve the interplay of ischemia and gastric outlet obstruction with gastroesophageal reflux. As this condition carries with it a mortality rate of nearly 40%, prompt recognition and aggressive management is of the utmost importance to prevent perforation or stricture. Considering this, AEN should be recognized as a possible outcome of an ischemic event and considered a potential cause of spontaneous esophageal perforation. Case Description/Methods: A 43-year-old female with a history of epithelioid hemangioendothelioma status post resection, Crohn’s colitis in remission, and recent hospitalization for a complicated urinary tract infection and abdominopelvic ascites concerning for malignancy with hospitalization complicated by cardiopulmonary arrest presented to the emergency department 8 days after discharge following a near syncopal episode. She was found to be hypotensive with tachycardia concerning for shock. She was started on broad spectrum antibiotics, 3 vasopressors, intubated, and admitted to the ICU. A CT scan of her chest, abdomen, and pelvis showed extensive pneumomediastinum concerning for esophageal perforation and pneumatosis intestinalis. Perforation was confirmed utilizing serial chest x-rays with contrast demonstrating a right-sided esophageal leak at the gastroesophageal junction. Both cardiothoracic surgery and gastroenterology were consulted, she was not deemed a surgical candidate and endoscopy with covered stent placement was planned. Endoscopy revealed a black esophagus consistent with an ischemic process throughout the entire esophagus and pneumatosis intestinalis suggesting small bowel ischemia. Stenting was aborted and the findings were discussed with the patient’s family who decided to pursue comfort measures. The patient died the following day (Figure). Discussion: It has been demonstrated that critically ill patients often experience low flow states, poor nutritional status, and disruption of intrinsic repair mechanisms. Coupled together, these insults increase the risk of developing AEN and must be acknowledged as a possible complication in this patient population. Although this is a rare condition, it should be recognized as a potential outcome of an ischemic event.Figure 1.: Images A-D depicts a diffusely abnormal mucosa throughout the esophagus, characterized by black/brown tissue consistent with ischemia.

S2471 Using Prokinetic Agents in Chronic Intestinal Pseudo-Obstruction (CIPO)

Introduction: Chronic intestinal pseudo-obstruction (CIPO) is a rare disease. Dilatation may involve the colon or small bowel and is usually due to an underlying neuropathic disorder. Clinical manifestations of CIPO include abdominal distention, bloating, and pain, which can be acute, chronic, or recurrent. Diagnosis of CIPO should be suspected in patients with these symptoms for at least 3 months in the absence of a mechanical cause. Diagnosis requires exclusion of mechanical obstruction and other causes of dysmotility (Table). Case Description/Methods: This is a case of a 62-year-old male presenting with 3 weeks of worsening abdominal pain and distention. History includes colon cancer with sigmoid resection/colostomy reversal, alcohol use disorder, and L5-S1 fusion on chronic opioids. He had 2 recent hospitalizations for similar symptoms thought to be due to non-obstructive ileus. At that time, colonoscopy showed significant colonic dilation with no masses or strictures. He was endoscopically decompressed and started on methylnaltrexone with relative improvement during a prior hospitalization. On this presentation, he had a massively distended abdomen with minimal tenderness. He was initially managed conservatively with bowel rest, rectal tube, and avoidance of opioids. However, serial abdominal X-rays showed no improvement in dilation (Figure). He was started on pyridostigmine with significant improvement in dilation and had normal bowel movements prior to discharge. Discussion: This patient had recurrent CIPO with multiple admissions without complete resolution of previously suspected non-obstructive ileus despite conservative management and methylnaltrexone. Imaging was consistent with severe colonic dilation. As the patient had no improvement with conservative management, he was started on a trial of pyridostigmine after which he had significant improvement of bowel dilation on X-ray with normal bowel movements, illustrating the role of prokinetics in treating suspected CIPO. Knowledge of CIPO is important to prevent delays in diagnosis. Intervention focuses on diet and treatment of the underlying disease. For patients with symptoms despite dietary modifications, prokinetics such as prucalopride or pyridostigmine can be used for symptomatic relief. Pyridostigmine has demonstrated efficacy in the chronic phase of CIPO in small observational studies and is more commonly used in pediatric CIPO. Through this case, prokinetic agents show promise for broader use in adult CIPO cases.Figure 1.: Abdominal X-Rays of patient before (A) and after (B) use of pyridostigmine showing improvement of colonic pseudo-obstruction. Table 1. - Acute Intestinal Pseudo-Obstruction vs Chronic Intestinal Pseudo-Obstruction (CIPO) Acute Intestinal Pseudo-Obstruction Chronic Intestinal Pseudo-Obstruction Prevalence 100 per 100,000* 0.80-1.00 per 100,000 Course Acute Chronic Presentation Abdominal distention Abdominal distention Cramping pain Abdominal pain Nausea/vomiting Bloating Anatomic involvement Colonic dilatation, usually cecum, right colon Colonic or small bowel dilatation Pathophysiology Multifactorial Neuropathic disorder of enteric or extrinsic nervous system Autonomic dysfunction strongly implicated Myopathic disorder of smooth muscle Malfunction of interstitial cells of Cajal Management Fluid resuscitation, correction of electrolyte abnormalities, avoidance of opioids/ anticholinergics Dietary modification, treatment of underlying disease Ambulation, bowel rest Prokinetics, such as Prucalopride, for symptomatic relief (Grade 2C) Decompression with nasogastric or rectal tubes Pyridostigmine in chronic phase of CIPO Pharmacologic treatment with neostigmine Operative intervention in cases of colonic perforation or ischemia *Inpatient admissions.

Right Phrenic Nerve Injury: A Rare but Possible Complication of Oesophageal Atresia and Tracheoesophageal Fistula Repair

Oesophageal atresia (OA) and Tracheoesophageal fistulas (TOF) are congenital anomalies commonly present in between 1 and 4 per 10 000 births, including stillbirths and termination of pregnancies. Currently, patients with these anomalies are are managed surgically, with common complications including oesophageal formation, anastomotic leakage and recurrence of TOF. This case report highlights the possibility of right phrenic nerve injury as a complication of OA and TOF repair. We report a baby boy born at term with worsening respiratory distress at day 15 of life, two weeks after undergoing an operation to repair OA and TOF. Since the surgery on day 2 of life, he could not be weaned off oxygen support successfully and had two episodes of worsening respiratory distress that was treated as pneumonia. Serial Chest X-Rays (CXR) showed a persistent elevation of the right hemidiaphragm. Ultrasound (USG) thorax supported the findings of right diaphragmatic paralysis by revealing minimal right diaphragm excursion with the paradoxical movement of the right diaphragm. He was initially managed non-operatively with non-invasive ventilation (NIV)/continuous positive airway pressure (CPAP) while monitoring for spontaneous recovery of the right diaphragm, which unfortunately did not occur. He was on NIV/CPAP for a total of 25 days and was tachypnoeic with mild subcostal recessions (SCR) and reduced breath sounds on the right throughout. Six weeks after the initial OA/TOF repair surgery, he was posted for Right Diaphragmatic Plication. Afterwards, he recovered well and was weaned off oxygen support within the next seven days and subsequently discharged.

Zip Line To Fracture Line: An Unusual Cause Of Pediatric Fracture

HISTORY: An 8-year-old male presented to the orthopedic clinic for follow up of a nondisplaced pathologic fracture. He was initially seen at an urgent care center with his mother, presenting with left lower leg pain after falling off a zip line at school. He was diagnosed with a pathologic fracture through an undifferentiated tibial diaphyseal lesion. He was placed in a splint followed by a long leg cast. He was sent for MRI and referred to orthopedic oncology for further diagnostic workup of his bone lesion. PHYSICAL EXAMINATION: Left lower leg: Positive for ecchymosis, swelling, and tenderness to palpation over the middle third of the tibia shaft. There are no gross deformities, skin breakdown, or tense compartments. DIFFERENTIAL DIAGNOSIS: 1.Nonossifying fibroma 2. Bone cyst 3.Osteofibrous dysplasia4. Adamantinoma TESTS AND RESULTS: X-Ray Left tibia/fibula: -“pathologic nondisplaced fracture of the tibia shaft. There is a discrete lesion of the tibia shaft with expansion of the cortex. No obvious periosteal reaction.”MRI Left tibia/fibula-“Distal tibial diaphysis expansile T2 hyperintense/T1 hypointense intramedullary lesion with associated cortical thinning”Follow up X-Ray Left tib/fib (16 weeks after fracture): -“Redemonstrated asymmetrically located lucency in the mid shaft tibia with scalloping.”FINAL/WORKING DIAGNOSIS:Osteofibrous dysplasia TREATMENT AND OUTCOMES:1.Treated with immobilization of the fracture 2.Returned to normal activities without pain at 11 weeks3.MRI showed findings concerning for osteofibrous dysplasia versus adamantinoma4. He had follow-up with the orthopedic oncologist and serial x-rays following the completion of his MRI5. After discussion at tumor board and little change on sequential x-rays, he was treated for presumed osteofibrous dysplasia6.He has since sustained a second pathologic fracture which is currently being treated with immobilization7.The surgery team discussed deferring surgical intervention due to his age

Multilayer Electrospun-Aligned Fibroin/Gelatin Implant for Annulus Fibrosus Repair: An In Vitro and In Vivo Evaluation.

Annulus fibrosus (AF) damage is proven to prompt intervertebral disc (IVD) degeneration, and unrepaired AF lesions after surgical discectomy may boost herniation of the nucleus pulposus (NP) which may lead to further compression of neural structures. Moreover, vascular and neural ingrowth may occur within the defect which is known as a possible reason for discogenic pain. Due to a limited healing capacity, an effective strategy to repair and close the AF defect is necessary. In this study, using electrospinning technology, two nature polymers, silk fibroin and gelatin, were linked to imitate the unique lamellae structure of native AF. Our findings revealed that a multilayer electrospun-aligned fibroin/gelatin scaffold with mechanical and morphological properties mimicking those of native AF lamellae have been developed. The average diameter of the nanofiber is 162.9 ± 38.8 nm. The young’s modulus is around 6.70 MPa with an ultimate tensile strength of around 1.81 MP along preferred orientation. The in vitro test confirmed its biocompatibility and ability to maintain cell viability and colonization. Using a porcine model, we demonstrated that the multilayer-aligned scaffold offered a crucial microenvironment to induce collagen fibrous tissue production within native AF defect. In the implant-repaired AF, H&E staining showed homogeneous fibroblast-like cell infiltration at the repaired defect with very little vascular ingrowth, which was confirmed by magnetic resonance imaging findings. Picrosirius red staining and immunohistochemical staining against type I collagen revealed positively stained fibrous tissue in an aligned pattern within the implant-integrated site. Relative to the intact control group, the disc height index of the serial X-ray decreased significantly in both the injury control and implant group at 4 weeks and 8 weeks (p < 0.05) which indicated this scaffold may not reverse the degenerative process. However, the results of the discography showed that the effectiveness of annulus repair of the implant group is much superior to that of the untreated group. The scaffold, composed with nature fibroin/gelatin polymers, could potentially enhance AF healing that could prevent IVD recurrent herniation, as well as neural and neovascular ingrowth after discectomy surgeries.

Giant bronchopleural fistula and empyema in a tuberculosis patient with diabetes mellitus: Vista from a high tuberculosis burden country in Southeast Asia.

Bronchopleural fistula is a pathological tract between the bronchial tree and the pleural space, which can be life-threatening due to tension pneumothorax. It is a rare complication in tuberculosis cases with highly variable in clinical manifestations and persistent air leaks which might lead to complications such as empyema. Herein, we present a tuberculosis and diabetic patient complicated with giant bronchopleural fistula and empyema. A 48-year-old man presented with shortness of breath for two weeks and cough with phlegm for two months. The patient was a smoker with severe Brinkman Index and diabetes. Physical examination revealed hyper resonant percussion and vesicular diminished on the left hemithorax. Laboratory results indicated the patient had anemia, leukocytosis, and hypoalbuminemia. GeneXpert sputum confirmed the presence of Mycobacterium tuberculosis and chest X-ray indicated a collapsed left lung. The patient was diagnosed with left secondary spontaneous pneumothorax, pulmonary tuberculosis, and diabetes. The patient was treated with chest tube drainage and anti- tuberculosis drugs. There was no improvement based on serial chest X-ray, and empyema appeared from the chest tube. CT-scan showed tuberculosis lesion, the collapsed of the left lung and fistula in segments 7-8 inferior lobe. Exploratory thoracostomy was performed, in which a giant bronchopleural fistula was detected and then repaired with BioGlue surgical adhesive. Unfortunately, the thoracostomy led to extensive subcutaneous emphysema and was treated by cervical mediastinotomy. The drainage was unable to be removed, and the patient was discharged with Heimlich-type drainage valves on day 28 of treatment. The empyema fluid was cultured and revealed Staphylococcus haemolyticus. This case highlights that tuberculosis could cause a bronchopleural fistula and empyema may occur secondary to late diagnosis that needs immediate surgery.

Neurotransmitter uptake of synaptic vesicles studied by X-ray diffraction

The size, polydispersity, and electron density profile of synaptic vesicles (SVs) can be studied by small-angle X-ray scattering (SAXS), i.e. by X-ray diffraction from purified SV suspensions in solution. Here we show that size and shape transformations, as they appear in the functional context of these important synaptic organelles, can also be monitored by SAXS. In particular, we have investigated the active uptake of neurotransmitters, and find a mean vesicle radius increase of about 12% after the uptake of glutamate, which indicates an unusually large extensibility of the vesicle surface, likely to be accompanied by conformational changes of membrane proteins and rearrangements of the bilayer. Changes in the electron density profile (EDP) give first indications for such a rearrangement. Details of the protein structure are screened, however, by SVs polydispersity. To overcome the limitations of large ensemble averages and heterogeneous structures, we therefore propose serial X-ray diffraction by single free electron laser pulses. Using simulated data for realistic parameters, we show that this is in principle feasible, and that even spatial distances between vesicle proteins could be assessed by this approach.

Development of a radiopaque tiltmeter to improve reproducibility for Fowler's position on chest radiography

IntroductionWe have developed a novel radiopaque tiltmeter (ROT) that can indicate patient tilt during a radiography examination and display it on X-ray images. This study evaluated the effect of variation of patient tilt on the reproducibility of Fowler's position for chest radiography and the accuracy of the ROT. MethodsWe evaluated the reproducibility of Fowler's position based on changes from the first day in the central venous catheter (CVC) tip position and the cardiothoracic ratio (CTR) with and without a digital tiltmeter to verify its efficacy in patients who underwent mobile chest radiography. The ROT contains radiopaque liquid consisting of white barium sulfate solution and oil and has a scale bar of 15°–75° with increments of 15° to indicate ROT tilt. The ROT tilt was increased from 10° to 80° in increments of 10°. We then evaluated (1) the difference between the ROT tilt and the tilt measured with a digital tiltmeter, and (2) the ROT tilt displayed on the X-ray image. ResultsWith regard to reproducibility in Fowler's position, changes in the CVC tip position were 2.8 ± 3.9 mm and 10.7 ± 10.6 mm with and without the tiltmeter, respectively (p < 0.05) and the respective rates of change in the CTR were 0.7% ± 0.6% and 4.0% ± 2.1% (p < 0.05). Differences between the ROT tilt and the tilt measured by the digital tiltmeter were within ±2.5°. All ROT tilts displayed on the X-ray images were recognized exactly as each tilt. ConclusionOur novel ROT had the potential to accurately indicate patient tilt during chest radiography, which could be helpful in terms of reproducibility and precise follow-up. Implications for practiceUse of the ROT for determination of patient tilt can improve reproducibility in Fowler's position, allowing more accurate serial X-ray imaging.

Tumor regression during radiotherapy as a predictor of response in locally advanced nonsmall cell carcinoma.

To compare the predicted response with observed response to treatment by measuring gross tumor volume-primary (GTVp) using onboard kilovoltage (kV) cone-beam computed tomography (CBCT), to analyze the serial tumor volumes during radiotherapy (RT) with serial tumor volumes during follow-up, and to identify the variables associated with survival outcomes. Between June 2017 and December 2019, 23 patients of histologically proven locally advanced nonsmall cell lung cancer (LA-NSCLC) received definitive chemoradiation. Serial kV-CBCT images X-ray volume imaging (XVI) were generated weekly for image guidance and were used to generate serial GTVp. Posttreatment follow-up images were used to generate follow-up GTVp. Relative volume regression (VR) during RT and relative response assessment (RA) during follow-up were defined from Avg Vol, of planning CT. The predicted progression model was generated from VR and analyzed against observed progression events. Regression-response model was generated to analyze VR against RA. The median XVI vol1, XVI vol2, and XVI vol3 were 78.123, 56.571, and 48.513 cc during the 2nd, 4th, and 6th weeks of RT, respectively. The median VR0 was 11.777% in the 2nd-week, VR1 was 20.959% in the 4th week, and 33.661% in the 6th week. The predicted responders and progression using the VR were similar to the observed response during the follow-up. The prediction of both RA0 and RA1 obtained from VR2 was statistically significant. Predication of RA0 from VR1 tended towards significant (P=0.084). VR2 was statistically significant in predicting RA2 (P = 0.04). The median progression-free survival (PFS) was not reached and the median overall survival (OS) was 24.2 months (95% confidence interval, 20.3-28.2 months). There was no statistically significant difference in PFS and OS between Avg Vol ≤ 99.5 cc and > 99.5 cc or other clinical parameters. Tumor regression during RT is a potential predictor of response in LA-NSCLC. kV-CBCT is a strong tool in assessing tumor regression during RT.

A cheaper external fixator for phalynx fractures of hand - functional outcome study

Background: Phalynx fractures account for 2.9% of fractures and are most commonly associated with machinery injuries in middle and young-aged individuals. Many external fixators are used for the fixation of phalanges with complexity which are costly. In this study, we used a cheap, easy fixator to construct and can be used as an emergency or definitive fixation. Aims and Objectives: The aim of the study was to evaluate the functional outcome after using a cheaper external fixator for phalynx fractures in place of costly mini external fixators for fixation which is used normally. Materials and Methods: We had done this study on 28 patients with phalangeal fractures, mostly due to machinery injuries which are open injuries (22 patients), with male predominance (20). The mean age group in our study was 34.89 years. The most common phalynx involved was the middle phalynx of the ring finger (11 cases). We made a fixator with syringe caps and K-wires as fixators. Results: Total active motion score used to assess the functional outcome after 3 months of follow-up and serial X-rays for assessing union. At the end of 3 months, 22 patients (78.5%) had shown excellent results, two patients (7.1%) had fair results, three (10.7%) had good results, and one patient (3.5%) had poor results. Conclusion: We suggest this fixator as this is cheap and easy to reconstruct with the instruments commonly available in OT. This fixator gives similar results to complex high-end fixators as compared to previous studies. This needs less expertise and training and is cost-effective for the patient.

Automatic Identification of Failure in Hip Replacement: An Artificial Intelligence Approach.

Background: Total hip arthroplasty (THA) follow-up is conventionally conducted with serial X-ray imaging in order to ensure the early identification of implant failure. The purpose of this study is to develop an automated radiographic failure detection system. Methods: 630 patients with THA were included in the study, two thirds of which needed total or partial revision for prosthetic loosening. The analysis is based on one antero-posterior and one lateral radiographic view obtained from each patient during routine post-surgery follow-up. After pre-processing for proper standardization, images were analyzed through a convolutional neural network (the DenseNet169 network), aiming to predict prosthesis failure. The entire dataset was divided in three subsets: training, validation, and test. These contained transfer learning and fine-tuning algorithms, based on the training dataset, and were implemented to adapt the DenseNet169 network to the specific data and clinical problem. Results: After the training procedures, in the test set, the classification accuracy was 0.97, the sensitivity 0.97, the specificity 0.97, and the ROC AUC was 0.99. Only five images were incorrectly classified. Seventy-four images were classified as failed, and eighty as non-failed with a probability >0.999. Conclusion: The proposed deep learning procedure can detect the loosening of the hip prosthesis with a very high degree of precision.

Respiratory Bronchiolitis-Interstitial Lung Disease in Chronic Kidney Disease Mimicking Uremic Lung: A Case Report

Introduction: Uremic lung is a frequent complication of chronic kidney disease (CKD), while interstitial lung is an inflammation of the parenchyma which impairs its capacity. These two conditions manifest similar radiological features with bilateral diffuse infiltrates. Therefore, their clinical appearance and radiological lesions are often mistaken. Case: This study reported a case of a 55-year-old male patient with shortness of breath for 1 month and worsening 1 week before hospitalization. The patient had a smoking history for 30 years with severe Brinkman index, hypertension (HT), and diabetes mellitus (DM). Auscultation examination showed crackles in both lungs, while laboratory results showed anemia, leukocytosis, increased urea and creatinine levels, and radiological features of bilateral infiltrate suggesting a uremic lung. Furthermore, the ultrasonography showed bilateral chronic pyelonephritis and was diagnosed with CKD, uremic lung, pneumonia, anemia, hypoalbuminemia, mild hypokalemia, DM, and HT. The patient was treated with regular hemodialysis three times a week, and the serial chest X-ray after hemodialysis showed persistent bilateral infiltrates. An MSCT examination was also performed, and the results showed respiratory bronchiolitis-interstitial lung disease (RB-ILD). The patient was treated with antibiotic therapy, inhaled salbutamol, systemic steroids, and mucolytics. The patient was discharged from the hospital after the respiratory complaint were improved. Conclusion: In uremia patients with bilateral infiltrates resembling uremic lung and unresponsive to hemodialysis or other therapies, interstitial illness should be explored. To improve patient management, risk factors for suspected interstitial lung disease should always be examined.

Prevalence and risk factors of fractures in transfusion dependent thalassemia - A Hong Kong Chinese population cohort.

ObjectiveTo delineate the prevalence and associated risk factors of low BMD, osteoporosis/bone fragility and fracture in transfusion‐dependent thalassemia (TDT) in the Chinese population in Hong Kong.Design, Patients and MeasurementsA retrospective cohort study design was employed. Patients of TDT who had serial Hologic dual‐energy X‐ray absorptiometry (DXA) from 2010 to 2016 and received regular transfusion for at least 5 years were recruited. Clinical and biochemical data, from 5 years before the first DXA scan, were retrieved from the electronic record system of the Hospital Authority, till 30 June 2020. Low bone mineral density and osteoporosis/bone fragility are defined by the ISCD 2019 position guidelines.ResultsSeventy‐seven patients were included in the analysis. The fracture prevalence of TDT among the Chinese population in Hong Kong was 15.58%. Up to 55.84% of patients had low bone mineral density, and 5.19% patients had osteoporosis/bone fragility state. The median age at first fracture was 31.73 years (range 24.06–44.18 years). In the regression analysis, a higher log(10) transformation of average ferritin levels over 5 years before the first DXA scan was significantly associated with fracture occurrence regardless of bisphosphonate treatment (OR 310.73, 95% CI 3.99–24183.89, p = .010). Mean average ferritin level over 5 years was 6695.5 ± 2365.7 pmol/L (fracture group) versus 4350.7 ± 3103.2 pmol/L (non‐fracture group), p = .016. Hip and spine BMD Z‐score did not have statistically significant association with fracture occurrence.ConclusionIron overloading plays an important role in adverse bone health in TDT. Dual X‐ray densitometry is insufficient in predicting fracture risk.

Intradiscal Injection of Autologous Discogenic Cells in Patients with Discectomy: A Prospective Clinical Study of Its Safety and Feasibility.

The treatment of intervertebral disc degeneration (IVDD) is still a huge challenge for clinical updated surgical techniques and basic strategies of intervertebral disc regeneration. Few studies have ever tried to combine surgery and cell therapy to bridge the gap between clinical and basic research. A prospective clinical study with a 72-month follow-up was conducted to assess the safety and feasibility of autologous discogenic cells transplantation combined with discectomy in the treatment of lumbar disc herniation (LDH) and to evaluate the regenerative ability of discogenic cells in IVDD. Forty patients with LDH who were scheduled to have discectomy enrolled in our study and were divided into the observed group (transplantation of autologous discogenic cells after discectomy) and control group (only-discectomy). Serial MRI and X-ray were used to evaluate the degenerative extent of index discs, and clinical scores were used to determine the symptomatic improvement. No adverse events were observed in the observed group, and seven patients in the control group underwent revisions. Both groups had significant improvement of all functional scores post-operatively, with the observed group improving more considerably at 36-month and 72-month follow-up. The height and water content of discs in both groups decreased significantly since 36 months post-op with the control group decreased more obviously. Discectomy combined with autologous discogenic cells transplantation is safe and feasible in the treatment of LDH. Radiological analysis demonstrated that discogenic cells transplantation could slow down the further degeneration of index discs and decrease the complications of discectomy.

Serial crystallography captures dynamic control of sequential electron and proton transfer events in a flavoenzyme.

Flavin coenzymes are universally found in biological redox reactions. DNA photolyases, with their flavin chromophore (FAD), utilize blue light for DNA repair and photoreduction. The latter process involves two single-electron transfers to FAD with an intermittent protonation step to prime the enzyme active for DNA repair. Here we use time-resolved serial femtosecond X-ray crystallography to describe how light-driven electron transfers trigger subsequent nanosecond-to-microsecond entanglement between FAD and its Asn/Arg-Asp redox sensor triad. We found that this key feature within the photolyase-cryptochrome family regulates FAD re-hybridization and protonation. After first electron transfer, the FAD•- isoalloxazine ring twists strongly when the arginine closes in to stabilize the negative charge. Subsequent breakage of the arginine-aspartate salt bridge allows proton transfer from arginine to FAD•-. Our molecular videos demonstrate how the protein environment of redox cofactors organizes multiple electron/proton transfer events in an ordered fashion, which could be applicable to other redox systems such as photosynthesis.